Suppose that the value of a stock varies each day from $13 to $24 with a uniform distribution. (a) Find the probability that the value of the stock is more than $17. (Round your answer to four decimal places.) (b) Find the probability that the value of the stock is between $17 and $21. (Round your answer to four decimal places.) (c) Find the upper quartile; 25% of all days the stock is above what value? (Enter your answer to the nearest cent.) (d) Given that the stock is greater than $16, find the probability that the stock is more than $20. (Round your answer to four decimal places.)

Respuesta :

Answer:

a. P= 0.6364

b. P = 0.3636

c. Q = $21.25

d. P = 0.5

Step-by-step explanation:

given data

value of a stock varies = $13 to $24

solution

P (stock value is more than $17)

P = [tex]\frac{(24-17)}{(24-13)}[/tex]

P =  [tex]\frac{7}{11}[/tex]

P = 0.6364

and

P (value of the stock is between $17 and $21)

P = [tex]\frac{(21-17)}{(24-13)}[/tex]

P = [tex]\frac{4}{11}[/tex]

P = 0.3636  

and  

Let the upper quartile be Q

[tex]\frac{(24 - Q)}{(24 - 13)} = 0.25[/tex]

[tex]\frac{(24 - Q)}{11} = 0.25[/tex]

(24 - Q) = 2.75

so

Q = $21.25

and

P(X > 20 | X > 16)

P = [tex]\frac{(24-20)}{(24-16)}[/tex]

P = [tex]\frac{4}{8}[/tex]

P = 0.5

Using the uniform distribution, it is found that:

a) 0.6364 = 63.64% probability that the value of the stock is more than $17.

b) 0.3636 = 36.36% probability that the value of the stock is between $17 and $21.

c) The upper quartile is of 21.25.

d) 0.5 = 50% probability that the stock is more than $20.

An uniform distribution has two bounds, a and b.  

The probability of finding a value of at lower than x is:

[tex]P(X < x) = \frac{x - a}{b - a}[/tex]

The probability of finding a value between c and d is:

[tex]P(c \leq X \leq d) = \frac{d - c}{b - a}[/tex]

The probability of finding a value above x is:

[tex]P(X > x) = \frac{b - x}{b - a}[/tex]

In this problem, varies each day from $13 to $24 with a uniform distribution, hence [tex]a = 13, b = 24[/tex]

Item a:

[tex]P(X > 17) = \frac{24 - 17}{24 - 13} = 0.6364[/tex]

0.6364 = 63.64% probability that the value of the stock is more than $17.

Item b:

[tex]P(17 \leq X \leq 21) = \frac{21 - 17}{24 - 13} = 0.3636[/tex]

0.3636 = 36.36% probability that the value of the stock is between $17 and $21.

Item c:

This is the 75th percentile, that is, the value of x for which P(X < x) = 0.75.

[tex]P(X < x) = \frac{x - a}{b - a}[/tex]

[tex]0.75 = \frac{x - 13}{24 - 13}[/tex]

[tex]x - 13 = 11(0.75)[/tex]

[tex]x = 21.25[/tex]

The upper quartile is of 21.25.

Item d:

Greater than $16, hence [tex]a = 16[/tex].

[tex]P(X > 20) = \frac{24 - 20}{24 - 16} = 0.5[/tex]

0.5 = 50% probability that the stock is more than $20.

A similar problem is given at https://brainly.com/question/13547683